JPH075623A - Photochromic glass thin film and its production - Google Patents

Abstract

PURPOSE:To easily produce a photochromic glass thin film having excellent weather resistance and high freedom degree for selection of transmission and absorption wavelength, CONSTITUTION:First, water containing 15% nitric acid is added to a soln. containing tetraethoxysilane, ethanol, and butanol, and mixture is stirred at room temp. to prepare a liquid (A). Then 6% spiropyran dispersion liquid is prepared by using polycarboxylic acid as a dispersant and isopropanol as a dispersion liquid to obtain dispersion of fine particles of 1'-butyl-3',3'-dimethyl-6- nitro-spiroindolinobenzopyran. This liquid is added to the liquid (A) and stirred at room temp. to prepare a liquid (B). This liquid (B) is applied on a glass substrate by dipping, dried in air at room temp., and heat treated to obtain a photochromic glass thin film. Characteristics of the obtd. thin film change shown as a curve 2 in the figure by irradiation of UV rays and as curves 3, 4, 5 and 1 by irradiation of visible rays.

Description

Detailed Description of the Invention

[0001]

The present invention relates to various recording materials, printing photoreceptors, laser photoreceptors, holographic materials, photochromic lens materials, optical filter materials, color filter materials for color television picture tubes, liquid crystal display materials, and automobiles. The present invention relates to a photochromic glass material used for light control windows, decorations, and the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, it has been known to use a color filter having a function of selectively absorbing light in various fields such as a display device and information recording. Conventionally known color filters are (1) an organic film filter in which an organic dye is added to an organic resin film such as a polyethylene film, (2) a mixture of an organic resin binder such as gelatin and polyester and an organic dye is printed. Or a filter formed on a glass substrate by electrodeposition coating, (3) Coloring glass filter prepared by adding transition metal or rare earth element ions to the glass substrate, or colloidal metal such as Au or CdS, or compound colloid deposition , (4) Evaporated metal filters using light transmission characteristics peculiar to evaporated metal.

In recent years, attention has been paid to various functions of dyes, and it has been proposed to use functional dyes in various fields. Photochromism is also one of the functions to which attention is paid, and is being studied in the fields of optical disks and the like.

The photochromism is a reversible action of irradiating a compound with ultraviolet light or sunlight containing ultraviolet light or light of a mercury lamp to develop or change color, and return to the original color when left in the dark or irradiated with visible light. Is. As a typical organic photochromic compound, there is a spiropyran compound,
Many derivatives are known (GH Brown, Photochro
mism, Wiely-interscience, New York, 1971). Also,
Spironaphthoxazine compounds and their substituted derivatives are also known (H. Durr and H. Bouas-Laurent, 4n + 2 s
ystems: Spiropyrans, Elsevier, New York, 1990).

In order to form a filter using this dye having photochromism, it is necessary to include a dye in the matrix, and conventionally, a polymer matrix was used.

[0006]

The conventional organic photochromic compound exhibits photochromic behavior even in a polymer matrix, but since the coloring species are unstable in the matrix, the organic photochromic compound develops a color upon irradiation with ultraviolet light and immediately disappears. It was colored.

The problems of the conventional color filter are as follows. Organic film filters, printing filters, electrodeposition filters, etc. all use organic polymers as binders for organic dyes, so they are easily deteriorated by ultraviolet light and their operating temperatures are limited.
On the other hand, since the colored glass filter itself is colored by the contained metal or metal ion, fading due to ultraviolet light is hardly observed, but it takes time to manufacture and the optical characteristic range such as transmission absorption wavelength is limited. An object of the present invention is to solve the above problems, to provide a photochromic thin film which has excellent weather resistance, is easy to manufacture, and has a high degree of freedom in selecting transmission and absorption wavelengths.

[0008]

In order to solve the above-mentioned problems, the present invention includes a matrix of a thin film made of an inorganic gel or glass formed on both surfaces or one surface of a glass or plastic substrate and the matrix. It is a photochromic thin film comprising at least an organic photochromic compound and a dispersant.

Further, Si, Ge, Ti, Zr, Al,
By carrying on a substrate a liquid prepared by dispersing an organic photochromic compound with a dispersant in an alkoxide or metacaptide solution of an element selected from P, Ca, Mg, Na, K, S and F, and drying or heating to form a film. The method is characterized by forming a matrix thin film of a photochromic inorganic gel or glass.

[0010]

In the past, the combination of an organic photochromic compound and an organic polymer had a problem in strength and weather resistance of the film itself. The inventors of the present invention have attempted to improve the stability and weather resistance of color-developing species by using an inorganic gel or glass that is relatively stable chemically and has excellent weather resistance as a matrix.

It has been found that the photochromic glass thin film according to the present invention develops a color upon irradiation with ultraviolet light, and that the colored species are stable even when the ultraviolet light is removed. Further, according to the present invention, since an inorganic gel or glass is used as a matrix instead of an organic binder such as gelatin, it has high weather resistance against ultraviolet light, temperature and humidity.

For example, as an organic photochromic compound, the following general formula (wherein R1, R2 and R3 are alkyl groups having 1 to 10 carbon atoms and R4 and R5 are various substituents)
The photochromic thin film in which the compound shown in (1) is dispersed in an inorganic matrix immediately develops a reddish violet color upon irradiation with ultraviolet light and does not disappear even if left in the dark for 24 hours, but is irradiated with visible light (> 390 nm). It has a characteristic that it returns to the original light orange color and repeats these coloring and decoloring.

[0013]

[Chemical 1]

As described above, the color-developing species are stabilized because the organic photochromic compound, which is an ultrafine particle having a particle size of 8 to 12 nm, is uniformly dispersed in a solution forming a matrix, and this is dried to form a film. It is considered that the distribution of the organic photochromic compound therein also has homogeneity at the molecular level.

That is, when the photochromic compound is agglomerated, the formation of the aggregate of the color-forming species becomes easier, and the stability of the color-forming species increases. However, excessive aggregation may deteriorate the transparency of the filter or cause the photochromic compound to be deposited as large particles.
In the present invention, a dispersant is used to prevent the aggregation that leads to the precipitation of the photocumic compound, thereby facilitating the formation of the coloring species as a highly concentrated dye solution and maintaining the transparency as a filter.

Further, since the coloring species of the organic photochromic compound become the coloring species, it is possible to relatively easily obtain a photochromic glass filter having desired spectral characteristics by finely changing the specific transmission absorption wavelength by controlling the molecular structure. it can. Further, a plurality of photochromic compounds can be mixed and used.

Photochromic compounds that can be used in the present invention include spiropyran compounds, spirooxazine compounds,
Examples include spironaphthoxazine-based, spirothiopyran-based, chromene-based, dichromene-based, fluorane-based, triphenylmethane-based, fluorenone-based, fulgide-based, and diarylethene-based photochromic compounds.

Examples of preferable organic photochromic compounds in the present invention are shown below. (A) is 1'-butyl-
3 ', 3'-dimethyl-6-nitro-spiroindolinobenzopyran, (b) 1'-butyl-3', 3'-dimethyl-spiroindolinonaphthoxazine, (c) 1'-propyl- 6-nitro-spirobenzothiazolinobenzopyran, (d) is spirodibenzopyran, (e)
Is 2,2-adamantylidene chromene, (f) is 1'-
Propyl-3 ', 3'-dimethyl-5'6-dinitro-
Spiroindolinobenzothiopyran, (g) is fluorane, and (h) is 1,1,1-tris (4-N, N-dimethylphenyl) ethanenitrile. Note that these molecules are examples and the present invention is not limited to these.

[0019]

[Chemical 2]

[0020]

[Chemical 3]

[0021]

[Chemical 4]

[0022]

[Chemical 5]

[0023]

[Chemical 6]

[0024]

[Chemical 7]

[0025]

[Chemical 8]

[0026]

[Chemical 9]

In the present invention, the matrix forming solution which is a dispersion medium of the photochromic compound and serves as a matrix is made of Si, Ge, Ti, Zr, Al, P, Ca, Mg,
It is an alkoxide solution or mercaptide solution of an element selected from Na, K, S and F, and metal alkoxides are mainly suitable. Metal alkoxides have the general formula M (O
R) represented by ₄ . Here, M is a metal element, and OR is an alkoxyl group. For example, Si (OCH ₃ ) ₄ , Si
(OC ₂ H ₅ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (OC
₃ H ₇ ) ₄ , Zr (OC ₂ H ₅ ) ₄ , Zr (OC ₃ H
₇ ) ₄ , Zr (OC ₄ H ₉ ) _{4 and the} like. Also,
As the mercaptide solution, various kinds can be applied like the alkoxide solution.

As the dispersant applicable to the present invention, polyvinyl butyral resin, for example, trade name S-REC BL-1, polyvinyl alcohol resin, for example, trade name Gocelan L-0301, acrylic resin, for example, trade name Hitec 532, ethyl cellulose. , Eg trade name ETHOCEL, unsaturated polycarboxylic acid, eg trade name BIC 1
04S, a phosphoric acid ester-based activator such as trade name DESCOL A-200, a polyester resin such as trade name Polyester WR-901, a silane coupling agent such as trade name KBM-502, and a titanium coupling agent such as trade name B. -1 (TBT), an aluminum coupling agent, for example, a trade name of aluminum chelate M and the like. The addition amount of these dispersants is preferably 5 wt% to 100 wt% with respect to the photochromic dye.

[0029]

EXAMPLES Examples of the present invention will be described below. (Example 1) First, 15% of a solution containing 16 g of tetraethoxysilane, 16 ml of ethanol and 24 ml of butanol was added.
16.0 g of water containing 0.2 ml of nitric acid was added, and the mixture was stirred at room temperature for 10 minutes, and this was designated as solution A.

Next, using polycarboxylic acid as the dispersant and isopropanol as the dispersion, 1'-butyl-3 ', 3'-
32 ml of a 6% spiropyran dispersion liquid in which dimethyl-6-nitro-spiroindolinobenzopyran ultrafine particles are dispersed is added to the liquid A, and well stirred at room temperature for 24 hours to obtain a liquid B.

This solution B was carried on a # S1111 glass substrate having a thickness of 1.0 mm by a dipping method, dried in air at room temperature, and then heat-treated in an electric oven at 100 ° C. for 15 minutes. The thickness of the film obtained is 300 nm.

The change in absorption spectrum of this film is shown in FIG. As shown in Characteristic 1 of Fig. 1, it shows almost no absorption above 500 nm, but it does not emit ultraviolet light (Xe lamp, 300 nm).
When the following light) is irradiated for 2 minutes, it changes like the characteristic 2,
It turned red purple. Even if this colored glass was left in the dark for 24 hours, no change in the absorbance was observed. However, the characteristic 3 → 4 →
The original color returned to 5 → 1.

FIG. 2 shows the relationship between the concentration of spiropyran with respect to tetraethoxysilane and the absorbance of the coloring species at 550 nm. From this figure, it can be seen that coloration is possible with a spiropyran concentration (wt%) of 7 to 12% with respect to tetraethoxysilane.

Further, FIG. 3 shows the time change of the absorbance A until the spiropyran thin film colored by irradiation with ultraviolet light is decolorized in the dark. From this figure, the half-life of the coloring species in the thin film made from tetraethoxysilane is 2.3 × 10 ⁵
s, the literature value in solution or in bulk glass 3 to 15
It can be seen that the color-developing species is remarkably stabilized as compared with s.

(Embodiment 2) FIG. 1 (b) is used for the liquid A of Embodiment 1.
3% dispersion liquid of 1'-butyl-3 ', 3'-dimethyl-spiroindolinonaphthoxazine shown in (3) was added, and a photochromic film was similarly prepared by a dip method.

This film turned blue upon irradiation with ultraviolet light, had a maximum absorption wavelength of 620 nm, and changed to its original color upon irradiation with visible light. The change in absorption spectrum of this film is shown in FIG. As shown in the characteristic 1 of FIG. 4, it shows almost no absorption in the visible region, but when it is irradiated with ultraviolet light (Xe lamp, light of 300 nm or less) for 2 minutes, the maximum absorption wavelength is 62 as shown in the characteristic 2.
The color changed to blue at 0 nm. Then, when the irradiation of ultraviolet light was stopped, the characteristics changed to 3 → 4 → 5 → 6 → 1 in FIG. 1 and returned to the original color. Characteristics 3, 4, 5 and 6 are 2 minutes after the irradiation is stopped,
The characteristics after 4 minutes, 10 minutes, and 60 minutes are shown. In this example, the original color returns to the original color 60 minutes after the irradiation of the ultraviolet light is stopped, but the stability is remarkably higher than that of the conventional polymer matrix.

In the case of this example, the relationship between the concentration of spironaphthoxazine with respect to tetraethoxysilane and the absorbance of the color-forming species was the same as in the example. (Example 3) A solution of a tetraalkoxide of titanium or zirconium, a β-diketone such as acetylacetone, and a dispersion of spiropyran were added to the solution A of Example 1 to obtain a # S1111 glass having a thickness of 1.0 mm. It is sprayed by a spray method and heated at 100 ° C. for 15 minutes to form a film. Even if the matrix is formed from a solution of zirconium tetraalkoxide as in this example, Example 1
A photochromic glass thin film similar to can be formed.

Example 4 A solution of titanium tetramethoxide in methanol is added to and mixed with a solution of silicon tetramethoxide, methanol and water. A liquid obtained by adding a dispersion of spiropyran to this liquid is supported on a glass surface (thickness 1.0 mm, # S1111) by a spin coating method (800 rotations) and heated at 100 ° C. for 15 minutes to form a film.

As in this embodiment, the matrix may be used by mixing a plurality of alkoxide solutions. Although all of the above-mentioned examples have been described with respect to a single-layer film, a film having two or more layers can be formed by repeating loading of a solution on a substrate and film formation by heating.

[0040]

According to the present invention, it is possible to easily form a photochromic glass thin film having excellent weather resistance and a high degree of freedom in selecting transmission and absorption wavelengths.

[Brief description of drawings]

FIG. 1 is a characteristic diagram showing a change in absorption spectrum of an example of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the concentration of a photochromic compound and the absorbance of a color-forming species in the example shown in FIG.

FIG. 3 is a characteristic diagram showing changes in absorbance in a dark place for the example shown in FIG.

FIG. 4 is a characteristic diagram showing a change in absorption spectrum of another example of the present invention.

[Explanation of symbols]

 1, 2, 3, 4, 5, 6 ... Absorption spectrum

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03C 1/00 531 9413-2H 1/725 503 9413-2H

Claims (5)

[Claims] 1. A photochromic material, which is formed on both surfaces or one surface of a glass or plastic substrate and comprises at least a matrix made of an inorganic gel or glass, an organic photochromic compound contained in the matrix, and a dispersant. Glass thin film. 2. The matrix composed of the inorganic gel or glass is Si, Ge, Ti, Zr, Al, P, C.
The photochromic glass thin film according to claim 1, comprising at least one element selected from a, Mg, Na, K, S, and F. 3. The photochromic glass thin film according to claim 1, wherein the organic photochromic compound is a mixture of one or more kinds of organic photochromic molecules. 4. Si, Ge, Ti, Zr, Al, P, C
a solution of an organic photochromic compound dispersed in an alkoxide or mercaptide solution of an element selected from a, Mg, Na, K, S and F on a substrate and dried or heated to form a film. Method for manufacturing photochromic glass thin film. 5. The method for producing a photochromic glass thin film according to claim 4, wherein the supporting of the alkoxide or mercaptide solution and the film formation by heating are repeated twice or more.